• Shigeo Hagiwara, Sumihisa Orita, Junichi Nakamura, Kazuhide Inage, Yohei Kawasaki, Yuki Shiko, Yawara Eguchi, and Seiji Ohtori.
• Department of Orthopaedics Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan. s_hagiwara@chiba-u.jp.
• Eur Spine J. 2021 Sep 1; 30 (9): 2443-2449.

PurposeRecent studies have revealed the impact of spinopelvic factors on the risk of dislocation after total hip arthroplasty (THA). This study examined the risk factors of impingement that can lead to dislocation using pre- and postoperative spinopelvic radiographs.MethodsWe studied 143 consecutive patients with end-stage hip osteoarthritis who were eligible for THA at our institute. Pre-operative pelvic incidence (PI), sacral slope (SS), lumbar lordosis (LL), sagittal vertical axis (SVA) in the standing and sitting position, and centre-edge angle (CE) were measured. The post-operative SS, LL, SVA, femoral shaft angle, and radiographic alignment of the acetabular component were also measured. We performed a multiple linear regression analysis to determine the risk factors for anterior and posterior impingement using pre-operative demographic and radiographic parameters. The clearance of anterior and posterior implant impingement was used for the surrogate-dependent variable for dislocation.ResultsA total of 95 patients were included in the analysis. There were significant differences in SS, LL, and SVA between the standing and sitting positions (P < 0.001). A multiple linear regression analysis showed that the PI-LL, LL changes, and CE were associated with the posterior impingement (β = - 0.21, 0.24, and -0.27, respectively). Moreover, PI-LL was also associated with the anterior impingement in the sitting position (β = - 0.27).ConclusionOur results suggest that a flatback with a rigid spine leads to posterior impingement, and a well-balanced spine leads to anterior impingement, which can be a potential risk factor for dislocation.© 2020. Springer-Verlag GmbH Germany, part of Springer Nature.

15 keywords...

hide…